Method of producing aluminum



(No Model.)

- J. B. HALL.

METHOD OF PRODUCING ALUMINUM. No. 503,929. Patented Aug. 22, 18'93 H N'i 'si :i iiml ,l.

UNIT D STATES PATENT OFFICE,

JOSEPH B. HALL, OF WHEELING, WEST VIRGINIA.

METHOD OF PRODUCING ALUMINUM.

SPECIFICATION forming part of Letters Patent No. 503,929, dated August22, 1893.

Application filed August 6, 1892- Serial No. 442,304.. (No specimens.)

To aZZ whom it may concern.-

Be it known that I, JOSEPH B. HALL, a citizen of the United States,residing at WVheeling, in the county of Ohio and State of West Virginia,have invented certain new and useful Improvements in Methods ofProducing Aluminum; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled .in the art to which it appertains to make and use thesame.

The object of this invention is to provide means more satisfactory thanany heretofore in use for producing aluminum from aluminous earths. Tothis end aluminous earth is treated with sulphuric acid which combineswith the aluminum forming a hydrated aluminum sulphate. heat and yieldsaluminum oxide, which in turn is reduced by electrolysis, the bathemployed being formed by fusing together aluminum chloride, sodiumchloride and lithium chloride, and the aluminum oxide being preferablysupplied by the constant decomposition of an anode of which the oxide isa constituent.

In the drawings,-Figure 1 is an elevation, partly in section, ofapparatus that I have employed in the practical use of the invention.Fig. 2 is a like view of the lower part of the apparatus slightlymodified as is hereinafter explained.

In Fig. 1 A is a suitable frame in which is mounted a vessel, orelectrolytic cell, B, preferably composed of carbon or of carbon andalumina. For strength, the vessel is preferably inclosed in an ironenvelope 0, both frame and envelope resting upon a suitablenon-conducting base. The vessel is provided with an outlet D near thebottom, and above the vessel the frame bears a holder F (without noveltyherein claimed) from which a large anode E depends in the axis of thevessel. This anode is formed from carbon and aluminic oxide intimatelymixed and is adjusted in vertical position by suitable devices,-shown inthis illustration as a nut I Working against the top ofthe frame upon arod supporting said holder. The anode and The latter is decomposed'bythe vessel B, or its envelope, are connected,

rides of aluminum, sodium and lithium. Now

if the parts be properly adjusted, the passage of the electric currentdecomposes the anode and the alumina therein is released and diffusedthroughout the bath and then reduced and the metal appears at thenegative electrode. At the same time the oxygen collects at the positiveelectrode where it combines with the carbon setting free more of thealuminic oxide. The reduced metal being of greater specific gravity thanthe bath collects at the bottom of the vessel and maybe drawn offthrough the outlet shown or maybe dipped from the vessel by the use of aladle of nonfusing material. The whole operation is antomatic if propermeans be employed to regulate the position of 'the anode, and it is onlynecessary to renew the anode from time to time as it is consumed and torestore in the bath such loss as may have arisen from volatilization, orfrom other causes. cient quantityof alumina in the bath increasesresistance and carbonous oxide appears and burns at the anode but if thequantity be sufficient, the gas liberated is carbonic anhydride.

While I have found it more satisfactory to difiuse finely dividedalumina through the bath by making it a constituent of the anode, sinceit seems to pass automatically to all parts of the bath and maintain auniform resistance to the current-,I have obtained tolerablysatisfactory results when omitting the alumina from the anode, in whichcase the alumina was added and stirred into the bath mechanically,either continuously or at in-..

bronze a mass of copper is placed in the bottom of the vessel, assuggested at X, Fig. 1. Now under the conditions existing when thealuminum oxide is reduced, the metal falling to the bottom of the vesselunites with tlie of aluminum chloride, sodium chloride and moltencopper. The process as before is conlithium chloride. I tinuous, itbeing only necessary to remove In testimony WhereofIaEfix my signaturein the bronze and to keep up the supply of coppresence of two witnesses.

5 per, in addition to the steps before mentioned. JOSEPH B. HALL.

What I claim is- Witnesses: For the electrolytic production of aluminumWALLACE GREENE,

from its compounds, a fused bath composed J. WM. HENRY.

